Final answer:
Ions are charged atoms or molecules formed when an atom gains or loses electrons; cations are positive ions formed by electron loss, while anions are negative ions formed by electron gain.
Step-by-step explanation:
An ion is an atom or molecule that has gained or lost electrons, resulting in a net electrical charge. Positive ions, or cations, form when an atom loses electrons, while negative ions, or anions, form when an atom gains electrons. For instance, when sodium (Na) loses an electron, it becomes a sodium cation (Na+) with a positive charge. On the other hand, chlorine (Cl) gains an electron to become a chloride anion (Cl-) with a negative charge. The names of anions are typically derived from the element and end in "-ide", such as chloride or sulfide.
Ions are crucial for creating ionic bonds, where a cation and an anion with opposite charges attract each other, just like magnets, to form a stable compound. This contrast in ion formation leads to many of the properties of ionic compounds, such as their tendency to dissolve in water, and their high melting and boiling points. Examples include sodium becoming Na+ (cation) and chlorine becoming Cl- (anion).